The present invention relates to a steel laminate gasket for an internal combustion engine with a cylinder liner therein.
In some engines, such as diesel engines, a cylinder liner is installed in each cylinder bore of an engine, wherein a steel laminate gasket is situated between a cylinder head and the cylinder liner. The conventional cylinder liner is provided with a cylindrical portion, a flange at an upper portion of the cylindrical portion extending radially outwardly from the cylindrical portion, and a projection extending upwardly from an upper end of the cylindrical portion. The thickness of the projection is substantially the same as or less than that of the cylinder liner.
In case a steel laminate gasket is installed in the cylinder liner, the gasket is mounted on the flange. The height or thickness of the gasket is made higher than the height of the projection, so that a small space is formed between the cylinder head and the projection of the cylinder liner. Further, since a bore of the gasket is made slightly larger than the outer diameter of the projection, an annular space is formed between the projection and the gasket. The annular space is not utilized, so that it is preferable to reduce volume of the annular space.
Japanese Utility Model Publication (Kokai) No. 57-10446 proposes an auxiliary sealing portion, which is formed inside a main sealing portion of a gasket. The auxiliary sealing portion may be formed by one of plates constituting a gasket, or formed separately. The auxiliary sealing portion operates to prevent the sealing pressure from concentrating at the flange of the cylinder liner as well as to reduce the annular space. However, since the rigidity of the auxiliary sealing portion is not strong, if high sealing pressure or high combustion pressure is applied to the auxiliary sealing portion, the auxiliary sealing portion can not seal properly.
Japanese Utility Model Publication (Kokai) No. 57-196244 proposes a fire ring, which is located inside the bore of a gasket. However, since the fire ring is manufactured separately from the gasket, it requires additional labor and expense. Also, it is not easy to assemble the fire ring and the gasket and to install them to the engine. Further, the Japanese publication No. 57-196244 proposes to provide two sealing portions in one gasket. If the sealing portions are located on the flange and the cylindrical portion of the cylinder liner respectively, the flange of the cylinder liner may be broken because of sealing pressure equally applied to the flange and the cylindrical portion. High sealing pressure can not apply to the cylindrical portion of the cylinder liner.
The present invention has been made to obviate the drawbacks of the prior art.
One object of the present invention is to provide a steel laminate gasket, which reduces volume of the annular space formed between a projection of a cylinder liner and the gasket.
Another object of the present invention is to provide a steel laminate gasket as stated above, which is provided with a rigid auxiliary sealing portion to improve sealing ability.
A further object of the invention is to provide a steel laminate gasket as stated above, which can be manufactured easily and economically.
Further objects and advantages of the invention will be apparent from the following description of the invention.